An improved source conversion unit of a charged particle beam apparatus is disclosed. The source conversion unit comprises a first micro-structure array including a plurality of micro-structures. The plurality of micro-structures is grouped into one or more groups. Corresponding electrodes of micro-structures in one group are electrically connected and driven by a driver to influence a corresponding group of beamlets. The micro-structures in one group may be single-pole structures or multi-pole structures. The micro-structures in one group have same or substantially same radial shifts from an optical axis of the apparatus. The micro-structures in one group have same or substantially same orientation angles with respect to their radial shift directions.

An improved source conversion unit of a charged particle beam apparatus is disclosed. The source conversion unit comprises a first micro-structure array including a plurality of micro-structures. The plurality of micro-structures is grouped into one or more groups. Corresponding electrodes of micro-structures in one group are electrically connected and driven by a driver to influence a corresponding group of beamlets. The micro-structures in one group may be single-pole structures or multi-pole structures. The micro-structures in one group have same or substantially same radial shifts from an optical axis of the apparatus. The micro-structures in one group have same or substantially same orientation angles with respect to their radial shift directions.

A charged-particle assessment tool comprising a plurality of beam columns. Each beam column comprises: a charged-particle beam source configured to emit charged particles; a plurality of condenser lenses configured to form charged particles emitted from the charged-particle beam source into a plurality of charged-particle beams; and a plurality of objective lenses, each configured to project one of the plurality of charged-particle beams onto a sample. The beam columns are arranged adjacent one-another so as to project the charged particle beams onto adjacent regions of the sample.

A charged-particle assessment tool comprising a plurality of beam columns. Each beam column comprises: a charged-particle beam source configured to emit charged particles; a plurality of condenser lenses configured to form charged particles emitted from the charged-particle beam source into a plurality of charged-particle beams; and a plurality of objective lenses, each configured to project one of the plurality of charged-particle beams onto a sample. The beam columns are arranged adjacent one-another so as to project the charged particle beams onto adjacent regions of the sample.

Beam intercept profiles are measured as a particle beam transversely scans across a probe. A current of beam particles, a detector intensity, or image pixel intensities can variously be measured to obtain the profiles. Multiple profiles are used to determine geometric parameters which in turn can be used to configure equipment. In one application, transverse beam intercept profiles are measured for different waist heights of the particle beam. Steepness of the several profiles can be used to determine a height of the probe as the height at which the profile is steepest. The known probe height enables placing the probe in contact with a substrate at another known height. In another application, transverse beam intercept profiles of orthogonal probe edges are used to position a beam waist, reduce spot size, or reduce astigmatism. Techniques are applicable to SEM, FIB, and nanoprobe systems. Methods and apparatus are disclosed, with variations.

Beam intercept profiles are measured as a particle beam transversely scans across a probe. A current of beam particles, a detector intensity, or image pixel intensities can variously be measured to obtain the profiles. Multiple profiles are used to determine geometric parameters which in turn can be used to configure equipment. In one application, transverse beam intercept profiles are measured for different waist heights of the particle beam. Steepness of the several profiles can be used to determine a height of the probe as the height at which the profile is steepest. The known probe height enables placing the probe in contact with a substrate at another known height. In another application, transverse beam intercept profiles of orthogonal probe edges are used to position a beam waist, reduce spot size, or reduce astigmatism. Techniques are applicable to SEM, FIB, and nanoprobe systems. Methods and apparatus are disclosed, with variations.

A charged particle assessment tool including: an objective lens configured to project a plurality of charged particle beams onto a sample, the objective lens having a sample-facing surface defining a plurality of beam apertures through which respective ones of the charged particle beams are emitted toward the sample; and a plurality of capture electrodes, each capture electrode adjacent a respective one of the beam apertures, configured to capture charged particles emitted from the sample.

A charged particle assessment tool including: an objective lens configured to project a plurality of charged particle beams onto a sample, the objective lens having a sample-facing surface defining a plurality of beam apertures through which respective ones of the charged particle beams are emitted toward the sample; and a plurality of capture electrodes, each capture electrode adjacent a respective one of the beam apertures, configured to capture charged particles emitted from the sample.

A difference between a calculated amount of drift and an actual amount of drift is reduced. According to one aspect of the present invention, a charged particle beam writing apparatus includes a deflector adjusting an irradiation position of the charged particle beam with respect to a substrate placed on a stage, a shot data generator generating shot data from writing data, the shot data including a shot position and beam ON and OFF times for each shot, a drift corrector referring to a plurality of pieces of the generated shot data, calculating an amount of drift of the irradiation position of the charged particle beam with which the substrate is irradiated, and generating correction information for correcting an irradiation position deviation based on the amount of drift, a deflection controller controlling a deflection amount achieved by the deflector based on the shot data and the correction information, and a dummy irradiation instructor instructing execution of dummy irradiation in a writing process to irradiate with the charged particle beam in a predetermined irradiation amount at a position different from the substrate on the stage.

A difference between a calculated amount of drift and an actual amount of drift is reduced. According to one aspect of the present invention, a charged particle beam writing apparatus includes a deflector adjusting an irradiation position of the charged particle beam with respect to a substrate placed on a stage, a shot data generator generating shot data from writing data, the shot data including a shot position and beam ON and OFF times for each shot, a drift corrector referring to a plurality of pieces of the generated shot data, calculating an amount of drift of the irradiation position of the charged particle beam with which the substrate is irradiated, and generating correction information for correcting an irradiation position deviation based on the amount of drift, a deflection controller controlling a deflection amount achieved by the deflector based on the shot data and the correction information, and a dummy irradiation instructor instructing execution of dummy irradiation in a writing process to irradiate with the charged particle beam in a predetermined irradiation amount at a position different from the substrate on the stage.